My favorite scripture.

"I urge you therefore, brothers and sisters, by the mercies of God, to offer your bodies as a living sacrifice, holy and pleasing to God, your spiritual worship. Do not conform yourselves to this age but be transformed by the renewal of your mind, that you may discern what is the will of God, what is good and pleasing and perfect........so we, though many, are one body in Christ and individually parts of one another." Romans 12:1-2, 5

How do I relate this to the virtue of kindness? God has asked us to love Him and one another. The ultimate sacrifice that Jesus Christ gave us was to offer His body for redemption of our sins. Greater love can no man give. Now Paul in Romans talks about our bodies as living sacrifices. This means that when we, still alive in body, learn to love, we die to our selfish self and live with more of Christ in us. This is our sacrifice, to give up the prideful parts of ourselves and learn to be kind to one another even when someone has hurt our feelings, rejected our ideas or been unkind to us. God asked us to sacrifice our pride and give to others what is pleasing to God. He said this because he knows that it is best for us.

Also, since we are "parts of one another" we are actually giving the kindness to ourselves too.  To offer genuine kindness means that we must be holding that kindness in our hearts. It changes our hearts and minds so that we can experience more of Christ in us. This is always good.

How do we do this? First, seek His Kingdom in prayer. Ask God to help you remove any bitterness or resentment from your heart. Cooperate with His grace. Sit in prayer in quiet and allow God to soften your heart. Choose to move in conversion towards Him.  Say goodbye to any parts of you that resist His Love. Let the grace of God fill you up with His living waters. Choose the beauty and goodness of His love. Choose to share that goodness, that kindness with someone who has hurt you. Let that person see and feel the light of Christ coming from you to them. Reconciliation and its healing is essential to God and a gift to us.